Most people know that racing operates in differences in thousandths of seconds, but there are other ways numbers can come bite you in the ass. Just ask Stoffel Vandoorne, whose pole position with Mercedes at the Valencia ePrix was taken away after just one wrong number.

Vandoorne nabbed what should have been pole position from defending series champion Antonio Felix da Costa by a mere 0.0028s. But now, he’s going to start from the rear of the grid because his lap times were deleted.

Why? One wrong number on the car’s technical passport.

This can be a little complex, but in the most basic sense, race cars are outfitted with all kinds of parts that are religiously tracked. For example, tires are barcoded. Every time a tire is put on a Formula E car, its barcode number is noted. After sessions, that number is checked again, either by race stewards performing a technical inspection or by the tire manufacturer, who generally takes the tires after each session in order to perform rigorous data analysis to evaluate that tire’s performance.

All those numbers are also entered in something called a “technical passport,” which is basically just a log that tracks every single part that’s on the car at any given time. It’s a fairly easy way to avoid last-minute swaps that would be deemed as cheating; if your passport doesn’t match what’s on your car, you’re going to be penalized. If the passport matches but there are other performance discrepancies, then officials can investigate for other issues. And, in a lot of ways, it’s an important way for the teams to evaluate the performance of each component of the car.

In Vandoorne’s case, his passport didn’t match his car after qualifying. More specifically, one single number was entered incorrectly when someone plugged in that tire’s serial number. Mercedes boss Ian James called it a case of “fat fingers” in a conversation with :

“What’s happened in this case is that instead of the number seven, a number eight has been put into an eight-digit serial number.

“Seven and eight are together on the keyboard so it’s a fat finger moment.

“Obviously, there were checks in place but the sheer volume of the parts that we have to enter, this is something that is relatively easy to do.”

James, of course, doesn’t feel the punishment fits the crime, which is to be expected—the last thing anyone wants is to suffer a penalty for something as simple as a typo. But those are, unfortunately, the rules of the game, and Mercedes is going to have a difficult time trying to salvage a top-10 finish out of what would have been a front-row start.